Initial eth_hedge_sim: P0 market, auth UI, one-click deploy.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/api/auth.py

@@ -0,0 +1,85 @@
+"""简单 HMAC Token 鉴权（无 JWT 依赖）。"""
+
+from __future__ import annotations
+
+import base64
+import hashlib
+import hmac
+import json
+import time
+from typing import Annotated
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
+from pydantic import BaseModel, Field
+
+from ..config import Settings, get_settings
+
+_bearer = HTTPBearer(auto_error=False)
+
+
+class LoginRequest(BaseModel):
+    username: str = Field(min_length=1)
+    password: str = Field(min_length=1)
+
+
+class LoginResponse(BaseModel):
+    token: str
+    username: str
+    expires_in: int
+    env_name: str
+    mode: str
+
+
+def _b64url(data: bytes) -> str:
+    return base64.urlsafe_b64encode(data).decode("ascii").rstrip("=")
+
+
+def _b64url_decode(s: str) -> bytes:
+    pad = "=" * (-len(s) % 4)
+    return base64.urlsafe_b64decode(s + pad)
+
+
+def issue_token(username: str, settings: Settings) -> tuple[str, int]:
+    exp = int(time.time()) + int(settings.auth_token_ttl_sec)
+    payload = {"u": username, "exp": exp}
+    raw = _b64url(json.dumps(payload, separators=(",", ":")).encode("utf-8"))
+    sig = hmac.new(
+        settings.auth_secret.encode("utf-8"),
+        raw.encode("ascii"),
+        hashlib.sha256,
+    ).hexdigest()
+    return f"{raw}.{sig}", settings.auth_token_ttl_sec
+
+
+def verify_token(token: str, settings: Settings) -> str:
+    try:
+        raw, sig = token.rsplit(".", 1)
+    except ValueError as e:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="invalid token") from e
+    expect = hmac.new(
+        settings.auth_secret.encode("utf-8"),
+        raw.encode("ascii"),
+        hashlib.sha256,
+    ).hexdigest()
+    if not hmac.compare_digest(expect, sig):
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="invalid token")
+    try:
+        payload = json.loads(_b64url_decode(raw))
+    except Exception as e:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="invalid token") from e
+    if int(payload.get("exp") or 0) < int(time.time()):
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="token expired")
+    username = str(payload.get("u") or "")
+    if not username:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="invalid token")
+    return username
+
+
+def require_user(
+    creds: Annotated[HTTPAuthorizationCredentials | None, Depends(_bearer)],
+    settings: Annotated[Settings, Depends(get_settings)],
+) -> str:
+    if creds is None or not creds.credentials:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="login required")
+    return verify_token(creds.credentials, settings)